It's kind of funny that when they created a character that was a living planet, Stan Lee and Jack Kirby apparently thought "Ego" was the most appropriate name. The whole planet is alive, so he's self-important?
That said, obviously he is. (I seem to remember him being rather less so in the later and somewhat miserable Silver Surfer cartoon; he was all quasi-benevolent earth spirit guy there, though he was still a villain and he actually worked for Thanos, if I recall. On one level, he wasn't as impressive [he couldn't even deal with the Silver Surfer very well], but on another, while the visuals they used for him were completely divorced from the original design they worked very well in animation.)
TMI for the day: My sister remarked once that she'd found crossover fanfiction involving Mogo the Green Lantern living planet and Zonoma Sekot, the living planet from Star Wars, and possibly Ego (my memory fails me on this point) having some form of relations.
(Also, notice the video is about Galactus and I don't even mention him?)